Improvement in augers



l UNITED STATES PATENT @errent HORAE T. LOVE, OF VERMILLION TOWNSHIP,MARSHALL COUNTY, KANS.

MPRGVEMENT BN UGRS.

Specification forming part of Letters Patent No. 50,88*?, dated November7, 1865.

W. LOVE ,& 0o., of New Yorkv city, have invented a new and usefulImprovement in the Double-Twist Anger and Auger-Bit, of which thefollowing isa fnll,clear, and exact description, reference being had tothe accompanying drawings, which form part of this specification, and inwhich Figure I represents a side elevation of my double-twist auger,and. Fig. II and Fig. III and Fig. IV end views of the same, whereinFig. IV is designed more particularly to show the diameter-line olnwhich the semicircloid edge isdrawn, as also the coalescencc of thatedge with screw and sour', which edge and its angular dispositionsconstitute my invention.

Angers `"as usually constructed are composed of three members-thecuttingbit, the screw, and the twisted pod, the 'latter acting todischarge the chips separated by the former, while the screw holds theedgein contact with the Wood as the angeris operated, and draws theauger forward in direction of its axis as the hole is bored. Thecutting-bit in double twist angers has two Hoor-lips, whosecuttingedges, either in or parallel to radial lines or pointed orslightly rounded within the coin pass of a quadrant and less, extendfrom the hase of thescrew vto the periphery ofthe auger, and thesecutting-edges are also disposed at a right angle to the axis of theauger. Angers thus constructed are'vcry defective-flirst, becansethe'cutting edge of the floor-lip, acting at` a right anglewith the axisofthe auger, cuts, in boring endwise,.the bers of the wood at a right.angle 5 and, second, in boring orosswise.

of the wood-gas when boring through a board,-

for example-the cutting-edge acting parallel with the grainsf the "wood,cleavesA or peels up, as iti-were, the chips, and the result is', thatin endwise'boring the resistanceo' the wood to edge of the auger isvery' great, and so great in sonne of 'the hard Woods that the an ger,when large, cannot be made to bore, and,-if made to bore at all, musthave great force applied to operate' it, and to the great danger ofbreakage and to the utter incapabilityin any case of rapid motion., Toremedy this defect in part the auger has been sometimes made withcutting-bit informofagougc; bntas this form of edge cuts but apart ot'the iiberstin 'endwise boring otherwise than at a right an'- gle, thedefect is at best but partially overcome, whileother evils ensue notnecessary 'nere to be particularly enumerated. In cross- Wise borlngthisright-angle edge to the axis ofthe auger, acting to cleave or peel upthe chips, as aforesaid, leaves these chips coarse andloing,according tothe dimensionsoi'the hole bored, so that the chips do not pass outfreely,.thereby choking up the pod and coinpclling the auger to befrequently withdrawn to clear ont the chips, and in deep boring, as

in mill and ship building, rendcringit almost useless.

Another great defect in this auger with cutting-edges in a plane at aright angle with the axis of the auger, is the fact that the wholelength of edge reaching Vthe opposite side ofthe wood bored through atone and the saine time is thus drawn through with lip and spur beforethe core of wood is completely cut out, thus leaving it to he removedroughly by moving auger to and fro, to scrapeout the saine with thetwisted pod,or incre smoothly by cutting it out with'a gouge. The spursdesigned to cut rouhnd the peripher Y of the wood to be removed, and soto make the outside ot' the hole smooth, contribute in this case only toineke the outside of the hole jagged, as they, too, are drawn throughbefore completing circle after the right angular cutting edges appear.

Auger-s as usually constructed are detective still further tronithe'fact that the cuttings-"1J, is not only at a right angle with thealxiszof the auger, as aforesaid, but, secondly,;1f`iom the fact thatthe cutting-edge is either in or pan ailel to a radial line from thebase of the screw to the @periphery of the twisted pod, or, at most,situated in a quadrantin other Words, that the' edge is straight,pointed, or slightly rounded, in contradistinction from beingseniicircular, and herein they are defective, iirst, from the fact that,beginning at the screw, each successive equal measure of the radial edgehas a very unequal amount of wood to out, so resisting thecutting-power. hy .aforos whose measure increases according to the lawof increase in the outer surfaces of concentric circles. To illustrate,I make a diagram as follows:

Let the circle drawn through e g represent the periphery of wood to bebored out by the cutting-edge c e, drawn in a radial line from S, thebase ofthe screw, to e in the periphery ofthe cylinder, where the edgeterminates, and let the radial distances a b, b c, ca', and d e beequaland represent equal measures ofthe edge. Now, when the edge a eacts by turning the anger, these fodr equal measures of edge willrespectively'deso ibe the four very unequal surfaces to be cut o `tembraced between the concentric circles respectively drawn through thepoints at a, b, c, d, and e. The laws of the circle willllctcrniine howunequal are these several surfaces to be cut out thus by different butecual portions ot' the edge. As the inequaliry ot' surface is so evidentbyinspection, 1 need not further demonstrate; and if at the pointu thecutting-edge should be constructed to y, making c c g the cutting-edgewith an angle atc, or by rounding the point cnnd making the edge c c g,the defect in question is not overcome, since the cutting-edge, whethera c y or we g, still remains With no regular ratio to the regularincrease of surface to be cut bythe respective portions ofthe edgerepresented bctween these concentric lines.

Anotherdefect in the cutting-edges constructed as aforesaid arises fromthe fact that in operating the auger the screw perforates and the spurscut slots in the woodto be removed, not by really detaching and liftingout the wood so displaced, but only by compressing and compacting thesame into the parts contiguous, and the result is that these displacedibers still remain to be cut cnt by the. edge of the bit as truly as itthey were originally where they are now, making in these contiguouspart-s a large increase ot' consolidated wood to be thus 'cut outwithout a corresponding additional measure oted ge or other advantage incutting.

Another defect in angers whose edge occupies in measure a quadrant andless, or even less than a semicircle, is the fact that when cutting withthe grain they move easily, and 'Iherefore faster, and when cuttingacross the grain they move hard, and therefore more slowly, (and theseconditions of cutting are found in all crosswise boring,) and the resultis that inequality of force is applied in every revolution of the auger,generating a wabbliug mctiou, and the hole isliable to be bored crooked,and not unfrequently is the pod ot' the auger bent or broken. .These areamong the more promiuentvdefects that I propose to overcome by myinvention.

My improvement consists -in constructing the cutting-edges of adouble-twist auger in the form of a semicircle whose radius is onehalf-ot the radius of the base of the screw added to one-halt' ot' theradius of the auger, and these semicircular edges are disposed withreference to the axis of the auger so as to form an obtuse angle ofabout one hundred and twenty degrees.

The instrument, as represented in the drawings, is constructed with adouble-twist pod, I, with two projecting spurs, S S, and with the siilcview of one edge, E,'in its angular relation to the axis of the auger,the heel only of the opposite edge being presented to vie`w in Fig. I,and with the two semicirculnr edges E E inFigs. II, III, and IV.representing end views of the auger of dil'erent sizes. The dotted linesin Fig'. IV are designed to be diameters, one drawn from the apex of thespur and the other from its cutting-base a at the point where the edgesot the spur. and floor-lip coalesce. In this latter line are situatedthe two centers on which the seniicircular edges E E respectively aredrawn. The angles by which the edge deflects from 'the base ot' thescrew and inilects to the periphery of the auger I call respectively theangles of deiiectionl and inflection. The size of the auger being thesaine, the larger the base ofthe screw the smaller will be the angles ofdeflection-and in ilection, and the'dilference between these two anglesrelatively is determined by the dierence between the radius of the augerand the radius ot` the base of the screw, the angle of inflection heiligalways thc smaller. The semicircloid edge is designed, therefore, tosustain a known relationshipto the size of the screw and to the anglesot' deflection and iniiection, which angles can be varied at pleasure tosuit diti'ereut sizes ot angers, and for other reasons, withoutdeparting substantially from the principles'of my invention, and which,indeed, is a part of it. Figs. II, III, and IV are designed, in part, toexhibit variations.

l. Now, as my auger is turned in the wood, in the rst place the edge ofthe door-lips being disposed at an obtuse angle with the axis of theauger, the following advantages ensue:

First, if boring endwise, the edge cuts the fibers oi' the woodobliquely, instead ot' cutting them at a right angle, and the resistanceof the Wood to the oblique cutting-edge is greatly diminished, and theincreased facility with which the wood is bored by the oblique cut maybe illustrated by the oblique stroke of the ax in cutting off va logcompared with the stroke perpendicular to the log.

Second, if my bliquely-cutting edge is used in boring crosswisc to thewood, as through a board or into the side of a stickof timber, then theedge thus disposed at an obtuse angle, instead ot' cleaving and peelingup, as it were, chips as long as the dimensions of the hole, cuts themlongitudinally crosswise and intermediately into small fragments, and sovthe chips pass Vout of the hole freely, instead of otherwise chokingthe pod and compelling the auger to be4 withdrawn to clear the chipsout.

Third, when the au ger makes its appearance on the opposite side of thewood to be bored through it cannot by its own action be forced throughthe opposite side of the wood until the whole core has been completelyrout out by the spurs, the reason whereof is that the two semicircloidedgesl,forming in rotating a cutting-wheel, are, in combination withtheir obtuse-angular disposition, resolved into a conical screw, as itwere, whose threads are these edges, 1 0 prevent the auger from escapingthrough the wood till having made at least one full revolution, whichrevolution thespur's must also make, and consequently must cutcompletely' round the core in .questiolrbefore the angercanpassthrougband -thelhole-iscut out smoothly to its completion.

IL The advantages in constructing the cut ting-edges of the door-lips inform of a semicirclcid nre First, that no one part of the edge h mayhave more fibers of wood to cut than has any otltiler one part of theedges of equal length; an

Second, since the semicircloid edge is more' than twice as long as themeasure of the distance from the base of the screw tothe peripher'yoftheauger', it follows that there are on an average more than two measuresof the edge appropriated to out out every one measure of wood to be cutout, and the beneficial result is that the cutting is performed afterthe manner of' the butchers knife, wherein itis drawn from heel towardthepoint across thevfibers to besev ered ,and not after the form ofachisel, wherein the cutting-edge and the wood tobe out is fin' lengthmeasnre formeasure.A `Thus the-whole ength ot' my semicircloid edge fromthe thread ot' the screw, of which it is a prolongation, to periphery ot' the auger, where it coalesces with the edgeA of the spur, draws'as'itcuts,`an'd`that, too, besides cutting at the aforesaid oblique angle;and this drawing ont 'thus is not only distributed to every part of thesemieircloid edge, but distributed (subject to the laws hereinindicated) in an increasing ratio as the edge D approaches the peripheryof the auger, thus compensating, and especially in large angers, for'the disadvantage at which fibers are cut at a distance from. the screw.Other things being equal, it requires much more 'force to cut a liber atone inch than at quarter of an inch from the screw. The regular ratiorequired to compensate obtains only in thesen'icircloid vtiguous tothe"aforesaidfpcrferations@fathescrew and the slot of the spurs,fwhilein very .large angers a quantity beyondthe'adj'ustable allotment, and invery. small angers short of` thc adjustable allotment, can by the samelaw be appropriated. Fourt 1,'in operation, the Atwo semicrcloid edgesbeing equivalent to the cuttingedges of a revolvingwheel, theyconsequently are cutting at 'one and the same time lengthwise,crosswise,"and interniediately in each and every'part ofthe cylinder,and they result is no inequality of force to operate is required, and nowabbling, with its attendantevils, ensues. Thus I have an auger of greateicieucy to bore any woods, hard or soft, endwise, crosswise, orintermediately, and at any depth o bore easily and rapidly, andsmoothly, and in a straight line, with no danger of choking up, iandnone, therefore, ofibending and breaking, having no neezl of withdrawingto clean out thee-hips, -andY-noavabblin-g motionfand .lear-V ing nocutting outot' cores tobe done. It will hold its edge long, because ithas a long edge to hold. lts edges, constructed oxra semicircle, withangles of'v deflection and inflection, for adjustment to all sizes ofangers, and for other purposes, and edges disposed at an ob tuse angleto its axis, my auger is essentially different in principle as well asin practice from the gouge-bit, or from the edge straight, rounded, orpointed,.dispcscd, as they are, at right angles to the axis of theauger, and ocA copying, as they do, the space of a quadrant or less inits periphery. From im perfection in machinery and otherwise, I do notconfine myself to mathematical exactitudes in construction so long asthe prin-I ciple is not thereby essentiallychanged; and l not claim therounded edge shown but not claimed by W. A. Ives in his model forpateut/of August 28, 1860, nor the same shown .iitLPiater 35,partjirsnsoitbelhno lggi cai Dictionaryof Techtt, nor tir-.esame inthetw-icerejected application of Grossman and Richardson,led January 1S,1853, these being'all subn stantially the same, and the edge soconstructed by them being in the form substantially elliptical with thefocus at the center of thelscrew. Said'edge meets the periphery of theauger nearly perpendicular to aline drawn tangent to thc periphery atthat point,anrl consequently said odge, though rounded',is neverthelessdiametrically opposite in principle to the cutting of my auger, both asto the quantity ot' wood to be cut by a given inea-sure of the edge andas to the` drayliiw et' the out,

The semicircloid erlgesfthe angles of 'dell iiection and inflection iiidisposing these edges intheir relation-to screw and periphery oi theauger, and the combination ot1 these edges with an obtuse-angulardisposition of them in their relation -to the axis of the auger, as andfor the purposes substantially set forth in the foregoing speoication.

Hardware house of Horace W, Love 85 Co., New York, August 1, 1865.

HORA-GE T. LOVE.

Witnesses JNO. H. NiooLAY, i WM. VAN VLEGK. f

